Sand used in foundry casting operations is a matter of some expense in the foundry process, particularly in the usual case where additives are included in the sand to make it more adaptable for the intended purpose. For this reason, it is desirable to reuse the sand in subsequent casting operations, and most desirable to prepare the sand for reuse without losing or destroying the relatively expensive additional materials which are included in the sand.
When sand is removed from the flask or mold in which the casting has been poured, it is quite hot and if merely piled on the floor and left to cool, a great deal of floor space would be required inasmuch as the middle of the pile would cool very slowly.
If sand is cooled by subjecting it to a blast or flow of cool air, cooling can be effected but a great deal of the fine additive material will be carried off in the airstream. This results in a requirement for a large bag room, i.e., an enclosure containing a large bag through which the air may pass but which tends to block passage of the fine particles. This is not only expensive, it also results in the loss of the fine additive materials from the foundry sand mix.